The purpose of the proposed research is to perform preliminary studies to purify and characterize the biochemical properties of a serine protease discovered in the seminal plasma of the domestic turkey Meleagris gallopavo. Results of pilot studies indicate that the enzyme(s) may have plasminogen activator properties. If so, it may be of value in human medicine as a therapeutic agent for the treatment of thrombosis in a variety of disease conditions. The specific aims are: 1.) to develop an efficient method for purification of the turkey seminal plasma protease(s) (TSPP) using isoelectric focusing, chromatofocusing, affinity chromatography and HPLC techniques; to determine the reaction kinetics of TSPP using a variety of synthetic substrates and inhibitors common to serine proteases 2.) to assay in vitro the ability of native TSPP to activate plasminogen or fibrinogen 3.) to determine the ability of native and acylated TSPP (with p-nitrophenyl p'- guanidinobenzoate;HCl) to dissolve ovine or porcine fibrin (blood clots in vitro). Both native and acylated plasmin and plasminogen activators have been used with success for treatment of thrombosis in humans, but with a low therapeutic index due to hemostatic breakdown and resultant nonspecific hemorrhaging. The long-term objectives of this research relate to evaluation of the usefulness of a newly discovered serine protease for purposes of blood clot dissolution. Success with in vitro studies will warrant further studies in vivo.